Abstract 14092: The Impact of Patient Comorbidity on Risk of 30-day Readmission Following Hospitalization for Acute Coronary Syndromes
Introduction: Readmission is common after hospitalization for acute coronary syndromes (ACS), and 30-day readmission rate has been proposed as a quality metric in this patient population. However, drivers of readmission remain poorly understood, and controversy remains on the extent to which patient characteristics such as comorbidity burden are major determinants of readmission risk.
Methods: We enrolled 874 patients hospitalized for ACS, and obtained records for all readmissions within 30 days of discharge. Patient comorbidity burden was assessed as tertiles of Charlson comorbidity index (CCI) due to skew. Other baseline demographic and clinical characteristics were compared between those who were and were not readmitted within 30 days. Covariates with p-values < 0.25 were included for multivariate logistic regression to calculate the adjusted odds ratio (OR) for 30-day readmission associated with the CCI. Harell’s c-statistic was calculated for the model with and without the CCI to determine if addition of the CCI improved model fit.
Results: Of the 874 patients hospitalized for ACS, 158 (18%) were readmitted within 30 days of discharge. The mean (SD) age was 63.6 (11.6) years, and 292 (33.4%) were female. In the multivariate model, patients in the highest tertile of the CCI had significantly higher risk for 30-day readmission compared to those in the lowest tertile (OR 2.02, 95% confidence interval [CI] 1.25-3.26, p=0.004), where as those in the middle tertile had similar risk (OR 1.01, 95% CI 0.61-1.70, p=0.99). The addition of CCI improved model fit significantly (Harell’s c-statistic from 0.62 to 0.65, p=0.04; Figure).
Conclusions: High comorbidity burden is independently associated with increased risk of readmission within 30 days of ACS hospitalization. These results may improve our understanding of which admissions can be preventable and can guide identification of patients at risk for readmission for targeted interventions.
- © 2013 by American Heart Association, Inc.